As known, the detergents used in the household, in commercial establishments and in industry, frequently contain large quantities of condensed phosphates, particularly tripolyphosphates. These are provided to sequester the hardness formers of tap water and are responsible to a great extent for increasing the cleaning power of the capillary-active washing substances. The phosphorus content of these agents has been criticized by the public in connection with questions of the protection of the environment. The view is frequently expressed that the phosphates, which arrive in the rivers and lakes after treatment of the sewage, have great influence on the eutrophication of the waters, and is said to lead to an increase of the growth of algae and of oxygen consumption. It has therefore been tried to eliminate phosphate from the washing and cleaning processes or from the agents used for this purpose, or at least to substantially reduce its proportion.
Copending, commonly-assigned U.S. patent application Ser. No. 458,306, filed Apr. 5, 1974, now abandoned, and its continuation application Ser. No. 800,308, filed May 25, 1977, now abandoned, and its continuation-in-part application Ser. No. 956,851, filed Nov. 2, 1978, discloses a process for the washing, bleaching or cleaning of solid materials, particularly textiles, by treating these materials with a liquor containing compounds able to bind the cations that make water hard. The process is characterized in that finely-dispersed, water-in-soluble silicate compounds having calcium-binding capacity of at least 50 mg CaO/gm of anhydrous active substance (AS) and having the formula I, combined water not shown EQU (M.sub.2/n O).sub.x. Me.sub.2 O.sub.3.(SiO.sub.2).sub.y (I)
where M is a cation of the valence n, exchangeable with calcium, x is a number from 0.7 to 1.5, Me is aluminum or boron, and y is a number from 0.8 to 6, preferably from 1.3 to 4, are suspended in the aqueous treatment bath. The process of the patent makes possible the complete or partial replacement of phosphates that bind calcium ions by complexing and are still being used in the washing and cleaning process.
The calcium-binding capacity of the above-defined compounds may reach values of 200 mg CaO/gm AS and is preferably in the range of 100 to 200 mg CaO/gm AS. The above-defined compounds capable of binding calcium are referred to as "aluminosilicates" in the following text, for the sake of simplicity. This applies particularly to the sodium aluminosilicates that are to be used preferably. All data given for their preparation and processing apply accordingly to the totality of the above aluminosilicate compounds as defined in said earlier application.
The cation M employed is preferably sodium. However, the same can also be totally or partially replaced by other cations exchangeable with calcium, such as lithium, potassium, ammonium or magnesium, as well as by the cations of water-soluble organic bases, for example, by those of primary, secondary or tertiary alkylamines or alkylolamines with not more than 2 carbon atoms per alkyl radical, or not more than 3 carbon atoms per alkylol radical.
The anhydrous active substance (AS) of the aluminosilicates is that reached after one hour of drying at 800.degree. C., whenever reference to anhydrous aluminosilicate is made in the following text. The adhering water as well as the water of retention is removed partically completely by this drying.
Aluminosilicates that are still moist, for example, from their preparation, are used to advantage as starting compounds in the preparation of washing and cleansing agent compositions containing the above-defined aluminosilicates in addition to the conventional components. The moist compounds are at least mixed with a portion of the remaining components of the material to be prepared, and the mixture is incorporated into the finished washing and cleansing agent composition to give as the final product, a product that is a pourable powder.
The aluminosilicates are supplied or used, in the framework of the procedure for the preparation of washing and cleansing agent compositions outlined above, as aqueous suspensions or as moist filter cake. Certain improvements of the suspension characteristics, such as the stability of the suspension and the transferability of the aluminosilicates dispersed in the aqueous phase, by pumping, would be desirable.